Gona rebuild my engine this winter, now im seeing 6-7 psi around 6000 rpm, Thats on ported heads, cc305, shorty hedders, stock comp.
After rebuild its gona be a 383 9.0 comp and twin highflow IC and the plan was to run around 10-12 psi.
What pulley size should i go for? Now its a 6.45 crankpulley and a 4.13 charger pulley.

 

I have a 3.4inch blower pulley and a 7.65 crank pulley and I see 10-11 pounds of boost now depending on weather conditons at 5900rpms. I also have 9:1 compression on a 383, cc305 cam but with Stock heads and Longtube headers a 3inch Y-pipe w/ dual random cats and Borla Catback and a Front mount 2 core intercooler. You may want to check out how I have my Airfilter routed with no flex tubing and see link in sig for all the details...

http://camaroz28.cardomain.com/memberpage/342629/2


Also the redline for the P1SC is 62,000 rpms.
With me shifting at 5900rpms I am only spinning the blower to ~54,500rpms so there is more room for more boost but I was told that the blower may not be efficient in that range plus my 2 core is currently is having a tough enough time to cool off for the boost I am making, let alone a few more pounds.

Hope that helps,
Claude

 

OK
Funny thing i was just looking at your site 10 min ago , (you can ignore the mail i sent to you) Looks like i should aim for 55000 rpms. That means i have to change bouth pullyes.
thanks

 

I have not gotten the email yet but I will disregard it

Also I have a 12 ribbed set up and you may want to look into getting the same type of set up to avoid any belt slippage. I recently heard ATI may not sell the 12 ribbed as a kit anymore so now you may have to buy each one indivually which means the cost goes up (Both Pullies, Tensioner, Belt..etc)

Either way Lonnie Pavtis is the man you wanna speak to, he can get you this stuff quickly and his customer service is excellent!!

His email addy is lpavtis@westol.com
And his webpage is www.westol.com/lpavtis

Thx,
Claude

 

Hmmm i used the adress you have registred on this forum...
Thanks , I have a friend who have a couple of pulleys left over, should se what size they are first.

 

I finally got it late yesterday.

Thats a good Idea, Most blower Pullies are stamped with the number and you can use this formula to find out what RPMs the Blower will be at when you spin your Motor to 6000rpms.

Crank Pully "divided by" Blower Pulley "Times" 4.1 PISC Internal Step-up ratio "Times" Motors Red Line (shift points) = Blower Rpms

Example for my car:
I have a 3.4 inch Blower pulley and
a 7.65 blower pulley.

7.64/3.4 = 2.25
2.25 * 4.1 = 9.225
9.225 * 5900 = 54427.5 Blower rpms


hope that helps.
Claude